Factor VIII (FVIII) is a protein found in blood plasma, which acts as a cofactor in the cascade of reactions leading to blood coagulation. A deficiency in the amount of FVIII activity in the blood results in the clotting disorder known as hemophilia A, an inherited condition primarily affecting males. Hemophilia A is currently treated with therapeutic preparations of FVIII derived from human plasma or manufactured using recombinant DNA technology. Such preparations are administered either in response to a bleeding episode (on-demand therapy) or at frequent, regular intervals to prevent uncontrolled bleeding (prophylaxis).
FVIII is known to be relatively unstable in therapeutic preparations. In blood plasma, FVIII is usually complexed with another plasma protein, von Willebrand factor (vWF), which is present in plasma in a large molar excess of the VWF subunit to FVIII and is believed to protect FVIII from premature degradation. Another circulating plasma protein, albumin, may also play a role in stabilizing FVIII in vivo. Currently marketed FVIII preparations therefore often rely on the use of albumin and/or vWF to stabilize FVIII during the manufacturing process and during storage.
The albumin and vWF used in currently marketed FVIII preparations are derived from human blood plasma, however, and the use of such material has certain drawbacks. A large molar excess of albumin compared to FVIII is typically added in order to increase the stability of the FVIII in such preparations, and this makes it more difficult to characterize the FVIII protein itself in these preparations. The addition of human-derived albumin to FVIII is also perceived as being a disadvantage with respect to recombinantly-produced FVIII preparations. This is because, in the absence of such added albumin, the theoretical risk of transmitting a virus would be reduced in recombinantly-derived FVIII preparations.
Several attempts to formulate FVIII without albumin or vWF (or with relatively low levels of these excipients) have been described. For example, U.S. Pat. No. 5,565,427 (EP 508 194) describes FVIII preparations which contain particular combinations of detergent and amino acids, specifically arginine and glycine, in addition to excipients such as sodium chloride and sucrose.
U.S. Pat. No. 5,763,401 (EP 818 204) also describes a therapeutic FVIII formulation without albumin, comprising 15-60 mM sucrose, up to 50 mM NaCl, up to 5 mM calcium chloride, 65-400 mM glycine, and up to 50 mM histidine.
U.S. Pat. No. 5,733,873 (EP 627 924) to Osterberg (assigned to Pharmacia & Upjohn) discloses formulations which include between 0.01-1 mg/ml of a surfactant.
Other attempts to use low or high concentrations of sodium chloride have also been described. U.S. Pat. No. 4,877,608 (EP 315 968) discloses formulations with relatively low concentrations of sodium chloride, namely 0.5 mM to 15 mM NaCl.
On the other hand, U.S. Pat. No. 5,605,884 (EP 0 314 095) teaches the use of formulations with relatively high concentrations of sodium chloride.
Further FVIII formulations are disclosed in WO 2010/054238, EP 1 712 223, WO 2000/48635, WO 96/30041, WO 96/22107, WO 2011/027152, EP 2 361 613, EP 0 410 207, EP 0 511 234, U.S. Pat. No. 5,565,427, EP 0 638 091, EP 0 871 476, EP 0 819 010, U.S. Pat. No. 5,874,408, US 2005/0256038, US 2008/0064856, WO 2005/058283, WO 2012/037530 and WO 2014/026954. EP 1 712 223 A1 discloses FVIII compositions comprising histidine and CaCl2, but the combined concentrations of histidine and Ca2+ in the compositions of EP 1 712 223 A1 are too low to confer the desired FVIII stability in aqueous solution.
Other therapeutic FVIII formulations of the prior art generally include albumin and/or vWF for the purpose of stabilizing FVIII and are therefore not relevant to the present disclosure.
One problem in the preparation of FVIII compositions is to provide a solution which is suitable for lyophilization and use after subsequent reconstitution. An important criterion in this regard is that the FVIII solution should show a stable FVIII activity and should show no turbidity prior to lyophilization. If an aqueous FVIII solution is turbid prior to lyophilization this is a clear sign that one or more substances in the solution, including FVIII itself, have aggregated. This is highly undesirable, as it is typically an indication of denatured protein, which leads to reduced activity. A second major issue with FVIII formulations is their stability after lyophilization. Signs of poor stability include a reduced remaining activity of FVIII after lyophilization, storage and reconstitution and the presence of high molecular weight complexes of FVIII.
Therefore, there is a great need for compositions comprising FVIII that do not show any turbidity or other relevant impairment of quality like e.g. significant loss of activity before lyophilization and possess long term stability after lyophilization at the same time. As the requirements of a stable solution prior to lyophilization and a stable lyophilisate in terms of composition may differ significantly, both conditions have to be considered when developing such a stable formulation.
It has now been surprisingly discovered that this can be achieved by compositions according to this invention, which comprise histidine and calcium at certain minimum concentrations. The inventors particularly found that, with respect to FVIII stability, a lower concentration of histidine can be balanced by higher calcium concentrations, and vice versa. This is, for example, not disclosed in EP 1 712 223 A1, and, consequently, the compositions described therein do not anticipate the subject matter claimed in the present invention. Specifically, the histidine concentrations of the compositions of EP 1 712 223 A1 are lower than required by claim 1 of the present application. The compositions of the present invention have an additional advantage in that they are close to physiologic conditions in terms of osmolarity. This avoids irritations or other local effects that might be caused by significantly hyper-osmolaric compositions that are present in many prior art formulations of Factor VIII.